Today I came across a short but very interesting study (unfortunately pay-walled) exploring the difference between White and black attitudes towards Jews. The thrust of it was that American Blacks are not more anti-Semitic than White people, they're just more polarized. Specifically, there are unique social threads pulling Black persons in both philo-Semitic directions (e.g., views of Jews as fellow victims or as liberal allies) and anti-Semitic directions (e.g., economic tensions or nationalistic scapegoating). The result is that while in the aggregate Black and White attitudes towards Jews are similar, Black views are more likely to be either strongly favorable or strongly unfavorable (whereas Whites tend to cluster in the middle).
The authors tested this along two dimensions: residential social distance (non-Jewish respondents asked if they would like to live in a neighborhood where the majority of residents were Jewish), and marital social distance (non-Jewish respondents asked if they would approve or disapprove of a close relative marrying a Jew). For both questions, Whites and Blacks in the aggregate had basically similar attitudes. But Black respondents were more likely to cluster at the poles (either strongly approving or strongly disapproving).
I've written several times on this blog against the notion that the Black community is particularly prone to anti-Semitism (which is not to say that there are no anti-Semitic Black people). This study, in addition to reinforcing that sentiment, also perhaps helps explain why some people seem to think that the Black community is particularly problematic in the respect. Sharp expressions of negativity probably stand out and stick in the mind more than strong positive feelings; hence, it is likely that in terms of recollection the two poles don't "wash out" and is more available than the other.
The study citation is David Raden, American Blacks' and Whites' Preferred Social Distance from Jews, 138 J. Soc. Psych. 265 (1998).